Add two control files to /proc/fs/nfsd:
* "stats_enabled" can be used to disable or enable the gathering
of per-client and per-export statistics in the server.
* "stats_prune_period" can be used to set the period at
which the pruning timer runs, in seconds. Unused stats
entries will survive at most twice that time.
Signed-off-by: Greg Banks <gnb@xxxxxxx>
---
fs/nfsd/nfsctl.c | 99 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 99 insertions(+)
Index: bfields/fs/nfsd/nfsctl.c
===================================================================
--- bfields.orig/fs/nfsd/nfsctl.c
+++ bfields/fs/nfsd/nfsctl.c
@@ -64,6 +64,8 @@ enum {
NFSD_Versions,
NFSD_Ports,
NFSD_MaxBlkSize,
+ NFSD_Stats_Enabled,
+ NFSD_Stats_Prune_Period,
/*
* The below MUST come last. Otherwise we leave a hole in nfsd_files[]
* with !CONFIG_NFSD_V4 and simple_fill_super() goes oops
@@ -92,6 +94,8 @@ static ssize_t write_pool_threads(struct
static ssize_t write_versions(struct file *file, char *buf, size_t size);
static ssize_t write_ports(struct file *file, char *buf, size_t size);
static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
+static ssize_t write_stats_enabled(struct file *file, char *buf, size_t size);
+static ssize_t write_stats_prune_period(struct file *file, char *buf, size_t size);
#ifdef CONFIG_NFSD_V4
static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
static ssize_t write_recoverydir(struct file *file, char *buf, size_t size);
@@ -113,6 +117,8 @@ static ssize_t (*write_op[])(struct file
[NFSD_Versions] = write_versions,
[NFSD_Ports] = write_ports,
[NFSD_MaxBlkSize] = write_maxblksize,
+ [NFSD_Stats_Enabled] = write_stats_enabled,
+ [NFSD_Stats_Prune_Period] = write_stats_prune_period,
#ifdef CONFIG_NFSD_V4
[NFSD_Leasetime] = write_leasetime,
[NFSD_RecoveryDir] = write_recoverydir,
@@ -1121,6 +1127,97 @@ static ssize_t write_maxblksize(struct f
return sprintf(buf, "%d\n", nfsd_max_blksize);
}
+extern int nfsd_stats_enabled;
+
+/**
+ * write_stats_enabled - Set or report whether per-client/
+ * per-export stats are enabled.
+ *
+ * Input:
+ * buf: ignored
+ * size: zero
+ *
+ * OR
+ *
+ * Input:
+ * buf: C string containing an unsigned
+ * integer value representing the new value
+ * size: non-zero length of C string in @buf
+ * Output:
+ * On success: passed-in buffer filled with '\n'-terminated C string
+ * containing numeric value of the current setting
+ * return code is the size in bytes of the string
+ * On error: return code is zero or a negative errno value
+ */
+static ssize_t write_stats_enabled(struct file *file, char *buf, size_t size)
+{
+ char *mesg = buf;
+ if (size > 0) {
+ int enabled;
+ int rv = get_int(&mesg, &enabled);
+ if (rv)
+ return rv;
+ /* check `enabled' against allowed range */
+ if (enabled < 0 || enabled > 1)
+ return -EINVAL;
+ /*
+ * We can change the enabled flag at any time without
+ * locking. All it controls is whether stats are
+ * gathered for new incoming NFS calls. Old gathered
+ * stats still sit around in the hash tables until
+ * naturally pruned.
+ */
+ nfsd_stats_enabled = enabled;
+ }
+ return sprintf(buf, "%d\n", nfsd_stats_enabled);
+}
+
+extern int nfsd_stats_prune_period;
+
+/**
+ * write_stats_prune_period - Set or report the period for pruning
+ * old per-client/per-export stats entries,
+ * in seconds.
+ *
+ * Input:
+ * buf: ignored
+ * size: zero
+ *
+ * OR
+ *
+ * Input:
+ * buf: C string containing an unsigned
+ * integer value representing the new value
+ * size: non-zero length of C string in @buf
+ * Output:
+ * On success: passed-in buffer filled with '\n'-terminated C string
+ * containing numeric value of the current setting
+ * return code is the size in bytes of the string
+ * On error: return code is zero or a negative errno value
+ */
+static ssize_t write_stats_prune_period(struct file *file, char *buf, size_t size)
+{
+ char *mesg = buf;
+ if (size > 0) {
+ int period;
+ int rv = get_int(&mesg, &period);
+ if (rv)
+ return rv;
+ /* check `period' against allowed range */
+ if (period < 10 || period > 14*86400)
+ return -EINVAL;
+ /*
+ * We can change the period at any time without
+ * locking. All it controls is the timeout on the
+ * next run of the prune timer. This might cause
+ * some unexpected behaviour if the period is
+ * changed from really high to really low.
+ */
+ nfsd_stats_prune_period = period;
+ }
+ return sprintf(buf, "%d\n", nfsd_stats_prune_period);
+}
+
#ifdef CONFIG_NFSD_V4
extern time_t nfs4_leasetime(void);
@@ -1263,6 +1360,8 @@ static int nfsd_fill_super(struct super_
[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
+ [NFSD_Stats_Enabled] = {"stats_enabled", &transaction_ops, S_IWUSR|S_IRUGO},
+ [NFSD_Stats_Prune_Period] = {"stats_prune_period", &transaction_ops, S_IWUSR|S_IRUGO},
#ifdef CONFIG_NFSD_V4
[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
[NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},
--
Greg
--
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